Bleach having stable brighteners

ABSTRACT

Liquid household bleach composition containing optical brighteners protectively carried in the bleach solution against chemical deterioration by a finely particulate sequentially prepared synthetic organic polymer which is dispersed through the bleach solution.

United States Patent Robinson et al. [451 Apr. 11, 1972 [54] BLEACHHAVING STABLE [56] References Cited I T BR GH ENERS UNIT ED STATESPATENTS [72] Inventors: Ronald A. Robinson, Garden Grove;

3,393,153 7/1968 Zrmmerer et al. ..252/95 33 9 3,544,500 12/1970 Osmondet al ...252/316 x 3,401,123 9/1968 Brynko et a1. 1 ..252/316 [73]Assignee: Purex Corporation, Ltd., Lakewood, Cal f 3,213,053 10/1965Kendrick ..1 17/ 100 A [22] Filed: 1970 Primary Examiner-Mayer Weinblatt[21] Appl. No.: 16,927 Att0rneyWhite, Haefliger and Bachand 52 us. 01..252/95, 252/187, 252/316, 1 [57] ABSIRACT 7 117/100 A Liquid householdbleach composition containing optical [51] Int. Cl. ..Clld 7/54brighteners protectively carried in the bleach solution against [58]Field of Search ..252/95, 187, 316; 1 17/ 100 A chemical deteriorationby a finely particulate sequentially prepared synthetic organic polymerwhich is dispersed through the bleach solution.

12 Claims, No Drawings BLEACH HAVING STABLE BRIGHTENERS BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention has to do withliquid household bleach generally used for whitening of fabrics inconjunction with detergents. Specifically, the invention is concernedwith improvements in conventional bleaches in both appearance andusefulness.

2. Prior Art It is the function of a liquid household bleach to removecolored impurities from fabrics by chemical conversion, e.g. intocolorless products as by oxidation. Alternatively blueing" of fabricsrenders invisible undesired color by color compensation.

It is currently popular to brighten fabrics beyond whitening them. Thisis today accomplished through the use of particular dyes, termed opticalbrighteners, in detergents. Similar to blueing, optical brightenerscompensate for a yellow cast in a fabric occasioned by absorption of theshort wavelength light by the fabric. Compensation is by way of partialreplacement of the absorbed or lost" light so that the eye sees acomplete white without loss of light. Optical brighteners introduceadditional light through fluorescence, that is, they absorb theinvisible ultraviolet portion of the daylight spectrum and convert theenergy there into visible light. Optical brightening thus effectivelyadds light to fabrics.

As stated, presently the mode of transferring optical brightener tofabric is by addition to wash water of the brightening compounds inadmixture with the detergent. Use of brightening compounds in bleachrather than detergent has been retarded by the known propensity ofbleach to oxidize and destroy most such compounds.

Bleach and detergent are used together in washing white fabrics. It hasbeen found that the bleach will destroy most optical brighteners presentin commercial detergents as well so that the net whitening-brighteningeffect of the bleach and optical brightener is not strictly additive.

Optical brighteners and nearly all dyes are sensitive to the chemicalaction of bleach. It has been proposed e.g. by Zimmerer in US. Pat. No.3,393,153 issued July 16, 1968, to mix brighteners with preformedpolymers, therein termed stabilizing agents, and by heating the mixtureto so associate the brightener and polymer that the stability of thelatter will somehow accrue to the benefit of the former. It would appearthat the bleach could have destructive access to any brightener combinedwith the polymer particles in this manner and that benefits inbrightener stability would be marginal and evanescent.

SUMMARY OF THE INVENTION It is a major objective of the presentinvention to provide both stable brightening and whitening in fabricwashing opera tions. Another objective is to provide a new source ofoptical brighteners for washing solutions. A further objective is toprovide optical brighteners in a form in which they are unreduced ineffectiveness by the conjoint presence of bleach. It is stillanotherobjective to provide increased substantivity of optical brightener tofabrics.

These and other objectives of the invention, to be made apparent as thedescription proceeds, are realized through the provision .of a liquidhousehold bleach composition comprising an aqueous solution of ableaching agent and an optical brightener in an effective amount, saidbrightener being protectively carried in the bleach solution by aspecially sequentially formed finely particulate synthetic organicpolymer which is dispersed through the bleaching agent solution.

Specifically the invention provides an optically brightened liquidbleach composition comprising an aqueous solution of a bleaching agentand an optical brightener in an effective amount. The brightener isprotectively carried in the bleach solution by a finely particulatesynthetic organic polymer carrier which is dispersed through thesolution e.g. in amounts between 0.05 and 5 percent by weight based onthe total weight of the composition. The carrier comprises polymerparticles typically between 0.5 and 2 microns in average particle sizeand having an inner portion consisting essentially of the opticalbrightener compound and a styrene-acrylic polymer and an outer portionforming an encapsulating layer over the inner portion and consistingessentially of styrene polymer free of the brightening compound, theparticles comprising per 100 parts by weight of polymer from 65 to 98parts of a styrene monomer having eight to 12 carbon atoms andconversely from two to 35 pans of methacrylic or acrylic acid monomercopolymerized therewith, the inner portion polymer containing a majorproportion but less than percent by weight of the styrene and at least amajor weight proportion of the acid monomer, with the outer portion ofthe particle polymer containing the balance of these monomers. From 0.5to 25 and preferably from five to 10 parts per 100 parts by weight ofthe polymer, of a hydrophilic comonomer may be employed in replacementof a like amount of styrene monomer, e.g. monomer selected from thehydroxyester, ether, amide and cyano derivatives of acrylic ormethacrylic and or a vinyl sulfonate monomer having the formula RCH=CH-SO3Me in which R is hydrogen or an aromatic or alkyl radical havingup to 10 carbon atoms and Me is an alkali metal.

The particles typically contain from 0.5 to 5 percent by weight of theoptical brightening compound, based on the weight of the styrene in thepolymer. The optical brightening compound may be selected fromderivatives of 4,4- diaminostilbene-2, 2-disulfonic acid,dibenzothiophene-5,5- dioxide, azole, coumarin, pyrazine and4-aminonaphthalimides. The polymer particles thus distributed in bleachhave been found to be highly substantive to fabric to carry the opticalbrightener through the wash cycle onto the fabric where it remains togive an appearance of brightness to the fabric. The aqueous solution ofbleaching agent typically has a pH of at least 10 and may include as thebleaching agent typically a hypochlorite ion generating compound such asthose generally used for bleaching e.g. a heterocyclic N-chlorimide orsodium hypochlorite, and the like, in amounts between 1 and 10 percentby weight.

The invention further provides a method of adding optical brighteners toa highly alkaline hypochlorite ion-containing solution which includesincorporating a brightener in the inner portion of a two layer syntheticorganic polymer particle and thereafter adding the carrier to thesolution. The brightener may be so incorporated by emulsion preparingthe polymer in the intimate presence of the brightener dissolved in thestyrene monomer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The liquid household bleachopacified in accordance with this invention may be any hypochlorite ioncontaining solution containing sufiicient free alkali to have a pH of 10and preferably 11.5 and higher, typically from 0.1 to 1.0 percent byweight free alkali. Per cent concentrations of hypochlorite ion willrange between 1 and 10 per cent by weight with a practical minimum being2.5 percent. Most bleaches contain between 3 and 7 percent hypochloriteion, and this concentration is most suited to use in the invention. Asmentioned above, various bleaching agents may be used including theheterocyclic N-chlorimides such as trichlorocyanuric acid,dichlorocyanuric acid and salts thereof such as the alkali metal saltse.g. sodium and potassium dichlorocyanurates. Other irnides arehypochlorite ion-generating also in aqueous solution and may be usede.g. N-chlorosuccinimide, N- chloromalonimide, N-chlorphthalimide and N-chloronaphthalimide. Other materials are the hydantoins e.g. thel,3-dichloro-5,5-dimethyl hydantoin, N-monochloro-C,C-dirnethylhydantoin, methylene bis (N-chloro-C, C- dimethylhydantoin),1 ,3-dichloro-5 -methyl-5-isobutyldimethylhydantoin,l,3-dichloro-5-methyl-5-ethylhydantoin,

1,3-dichloro-5-methyl- Sn-amylhydantoin and the like as well astrichloromelamine. Preferred sources of hypochlorite ion are the watersoluble inorganic salts such as lithium, calcium, potassium and,particularly, sodium hypochlorite.

The insoluble synthetic organic polymer component of the presentcomposition is of a particle size and constitution permitting suspensionin the aqueous hypochlorite ion solution. Particle size on average willgenerally range between 0.01 and 5 microns and preferably 0.5 and 2microns. Concentrations of the polymer particles will range from aneffective amount for imparting added brightness through deposition ontofabric of the contained optical brightener to that amount forming adeposit visible as such on fabric. Convenient concentrations in thebleach solution are between 0.05 and 5 per cent by weight, with 0.3 to 3per cent by weight being particularly preferred.

Preferred polymer particles will exhibit an index of refraction morethan 0.05 unit greater than the index of the aqueous, e.g. hypochloriteion solution. As such, the polymer particles are perceptible as acomponent of the composition although not individually visible, i.e. anopacity is imparted to the bleach composition.

The safe incorporation of optical brighteners and other dyes in aqueousbleach according to the invention is realized by combining the opticalbrightener compound in a polymer in a manner to insulate the brightenersfrom the harsh environment while permitting its useful brighteningfunction. To so combine the brightener compound with polymer, thebrightener is first dissolved in the oil-soluble monomer of the polymerand the monomer-brightener solution is copolymerized with vinyl acid,i.e. acrylic or methacrylic acid which has been previously dissolved inwater, by conventional emulsion polymerization techniques. Subsequentlya second emulsion polymerization is effected to coat the particlesresulting from the first polymerization with a bleach impervious polymerfree of brightener thus to protect the brightener compound in the firstor inner center portion of the polymer particle. While the emulsionrecipies are conventional, the sequence of operations is notconventional and enables the realization of the invention.

It is known to emulsion polymerize styrene and acrylic acid bydissolving an emulsifying agent in all the water and adding the acrylicacid and possibly a hydrophilic comonomer. Styrene or other oil soluble,principal monomer is added to the mixture and stirred to achieveemulsification. The temperature of the emulsion is raised to 120-l40 F.and a persulfate or peroxide catalyst is added with or without areducing agent to form a redox couple to produce free radicals toinitiate the polymerization reaction. The temperature of the emulsionrises exothermically as the monomer species are converted into polymer.Usually no external heat is required and almost all of the monomer ispolymerized to provide a milky aqueous suspension of particles (a latex)in which the particles typically range from 0.5 to 2 microns in averageparticle size and contain about 30 to 60 percent of the total polymer.

In preparing compositions according to the present invention, the abovecommon procedure is modified to achieve the purposes of the invention.Thus only a portion of the monomer components are first reactedtogether. And the brightener is first dissolved in the oil-solublemonomer (styrene) to assure intimate incorporation of the brightenercompound in the polymer. In a second stage of the preparation thebalance of the monomers is added and after sufficient intermixing andaddition of catalyst, a second emulsion polymerization is effected toovercoat the first formed particles with additional, separately formedpolymer which it has been found will protect the brightener in the firststage polymer.

While not wishing to be bound to any particular theory of operation itis believed the remarkable stability of the brightening compound in thebleach compositions of the invention against oxidative attack may derivefrom the formation of micelles upon the addition of theemulsifier-surfactant to water. The micelles are lamellar colloidalparticles having structures dependent on the hydrophobic/hydrophilicorientation of the surfactant molecule. Upon the addition of thehydrophobic (styrene) monomer containing dissolved dye in the firststage of preparation, these monomer droplets and hydrophilic monomerbecome encapsulated in the micelles. Addition of catalyst causespolymerizaion to proceed within the confines of the micelle until ahard, discrete particle of polymer is formed, still enveloped by themicelle structure. Upon the addition of the second portion of thehydrophobic (styrene) monomer, in the absence of additional surfactantfor formation of new micelles, the added monomer enters the previouslyformed polymer particle micelles and forms a layer of reactive monomerover the outside of the polymer particles. With the addition of morecatalyst, this newly added monomer polymerizes and forms a shell ofbasically hydrophobic polymer over the inner particle portion containingthe brightener compound. This shell prevents chemically active moleculessuch as oxidizing molecules of bleach from entering the particle to thebrightener compound. The second added portion of hydrophobic monomer maycontain brightener compound, but such compound in theouter layer of theparticles is readily destroyed in contact with bleach.

The particulate polymer in which the brightener compound protectivelyinheres consists essentially of a styrene monomer, acrylic ormethacrylic acid and optionally a second hydrophilic comonomer.

As the hydrophobic monomer component there may be employed styrene perse, i.e. vinyl benzene, or a substituted styrene such as vinyl tolueneor butyl styrene, i.e. alkyl substituted styrenes in which the alkylgroups contain from one to four carbon atoms such that the styrenemonomer contains from eight to 12 carbon atoms, inclusive. Or thestyrene monomer may be monohalogen ring substituted such aschlorostyrene or bromostyrene. The acid component may be describedgenerically as a water-soluble a, B ethylenically unsaturatedmonocarboxylic acid, i.e. vinyl acid having three to four carbon atomsnamely acrylic or methacrylic acids. The proportion by weight ofcombined styrene monomer and acid monomer in the particulate polymerranges between 65 to 98 parts styrene and two to 35 parts of the vinylacid per 100 parts by weight of the terpolymer.

Polymerization is carried out as hereinafter described to providepolymer particles ranging in size between 0.01 and 5 microns andpreferably between 0.5 and 2 microns where an opacifying effect isdesired. It is often desirable to incorporate a further monomer in thepolymer. This additional monomer will be a hydrophylic monomer such as aderivative of methacrylic or acrylic acid containing up to 10 carbonatoms and free of carboxyl groups. Thus, such derivatives as the ester,hydroxyester, ether, amide or cyano derivatives of acrylic ormethacrylic acids may be used in amounts of between 0.5 and 25 andpreferably five and 10 parts by weight, in substitution for an equalweight amount of the styrene monomer, per 100 parts of the finalopacifying polymer. A water-soluble vinyl sulfonate monomer may be theadditional hydrophilic component, e.g. having the formula R-CH CHSO Mein which R is a hydrocarbon radical free of aliphatic unsaturationhaving up to 10 carbon atoms, e.g. an aromatic radical such as tolyl,benzyl or phenyl radical; an alkyl radical such as methyl, ethyl,propyl, butyl, isobutyl, pentyl, neopentyl, hexyl, heptyl, octyl,2-ethyl hexyl, nonyl and decyl, or hydrogen and Me is an alkali metal,e.g. sodium, potassium, lithium and cesium. Specific termonomers ofchoice include the hydroxyalkyl esters of methacrylic acid in which thealkyl group contains from one to four carbon atoms and particularlyhydroxyethyl and hydroxypropyl methacrylate, and acrylamide,methacrylamide, acrylonitrile, methyl vinyl ether, sodium or potassiumvinyl sulfonate and styrene sulfonate.

The monomers just described are emulsion polymerized using conventionalcatalysts, oxidizers or reducers, temperatures and pressures but withthe critical steps of first dissolving the brightener compound in thestyrene monomer and dissolving the water-soluble vinyl acid andhydrophilic comonomer, if used, in water, suitably with the emulsifyingsurfactant, prior to addition of the styrene. Apart from the hereindiscussed sequential reactant additions, the preparation of the polymersis carried out as for any other exothermic emulsion polymerization ineach stage. Thus an aqueous solution of a suitable surfactant is mixedwith the water soluble vinyl acid. Thereafter the water-soluble styrenereactant into which the brightener compound has been previouslydissolved, suitably at concentrations between 0.5 and 5 percent based onthe total of styrene in the polymer and preferably at least 1 percent byweight, same basis, is mixed in and agitated until emulsified as the oilphase. The emulsion is then maintained at an elevated temperaturethrough exothermic and/or added heat if necessary in admixture with asuitable catalyst, e.g. and preferably water-soluble persulfates such asammonium and sodium and potassium persulfate and peroxides, e.g.hydrogen peroxide; and also catalysts such as t-butyl perbenzoate andtbutyl hydroperoxide, as well as other oil-soluble materials such asbisazobutyronitrile and cumene hydroperoxide. Following reaction for therequired period and at temperatures between l30200 F. and boiling thereaction mixture is cooled and neutralized with alkali. The latex may bespray or otherwise dried without loss of dispersibility or stability inliquid household bleach.

In the preparation of brightener protective polymer particles for use inthe present invention, the hydrophobic monomer, e.g. styrene is dividedinto two portions for separate, sequenced emulsion polymerizations. Thefirst portion, for the first emulsion polymerization comprises a majorweight proportion, but less than all of the styrene to be used infonning the polymer, i.e. at least 50 percent by weight of the 65 to 98parts by weight of styrene ultimately to be used per 100 parts ofpolymer is employed in the first polymerization. All of the opticalbrightener to be incorporated in the polymer is dissolved in this firstportion of styrene. As indicated elsewhere this will be from 0.5 to 5percent by weight of brightener compound based on the total weight ofstyrene monomer in the polymer. Preferably at least 1 percent by weightof brightener is dissolved in the first styrene portion. The firststyrene portion will generally be less than 90 percent by weight of thetotal polymer styrene content and will typically be between 60 and 80percent by weight of the polymer total styrene content.

The acrylic or methacrylic acid comonomer may also be divided into twoportions for sequential polymerization. The first portion employed inthe first polymerization, will be a major weight proportion of the acidin the total polymer, i.e. at least 50 percent by weight of totalpolymer acid. This first portion may range up to 100 percent by weightof the total polymer portion of acrylic or methacrylic acid,.buttypically from 60 to 80 percent of the total polymer acid will beincluded in the first acid portion.

As mentioned above from 0.5 to 25 and preferably from five to parts byweight of the styrene monomer may be replaced on a weight for weightbasis by certain hydrophilic comonomers. This substitution may be madein either the first or second styrene monomer portion, and preferablyfrom 60 to 80 percent by weight of the added hydrophilic comonomer isincorporated in the first styrene portion.

The balance of each monomer comprises a second portion for use in thesecond emulsion polymerization.

With the monomers having been thus divided for two polymerizations, theoptical brightener is dissolved in the styrene monomer first portion.The acid first portion is dissolved in water and the two solutions aremixed together in a suitable vessel. The mixture is emulsion polymerizedby the conventional'techniques above described by adding a surfactant, apolymerization catalyst and heating. Heating is initially to about 130F. but the temperature rises with the reaction exotherm to about 190 F.or somewhat higher or lower. The first reaction product is a latex ofstyrene-acid polymer (or terpolymer with the hydrophilic comonomer)having from 30 to 60 percent by weight of polymer present as particlessuspended in and aqueous medium.

The reaction product is cooled before the next stage of polymerization.Cooling typically will be to less than F., or the reaction initiationtemperature of the second polymerization mixture. The reaction mixtureis prepared by adding the balance of each of the monomers to the cooledfirst polymerization reaction product. The mixture is mixed together andpermitted to stand from 15 to 30 minutes or longer. Thereupon additionalpolymerization catalyst is added and the temperature of the reactionmixture permitted to rise above 130 F. to F. or higher or lower, withthe reaction exotherm. Reaction is continued to produce a latexcontaining polymer particles having an average particle size between 0.5and 2 microns. The optical brightener is within these particles andprotectively carried there. Suitable surfactants for efi'ecting emulsionpolymerization as described and/or for suspending the finely particulatepolymer in bleach or other aqueous liquid are the noncationic types,i.e. anionic, nonionic or amphoteric. Various of these surfactants willshow greater or less tolerance for the harsh environment of liquidhousehold bleach, depending on the concentration and pH thereof.

Among suitable surfactants are anionic aromatic compounds, e. g.water-soluble higher alkyl aryl sulfonates particularly those havingfrom eight to about 15 carbon atoms in the alkyl group. It is preferredto use the higher alkyl benzene sulfonates, although other mononucleararyl nuclei, such as toluene, xylene, or phenol, may be used also. Thehigher alkyl substituent on the aromatic nucleus may be branched orstraight chained in structure, examples of such group beingnonyl,dodecyl and pentadecyl groups derived from polymers of lowermono-olefins, decyl, keryl, and the like.

Illustrative of suitable aliphatic anionic compounds are the normal andsecondary higher alkyl sulfates, particularly those having about eightto 15 carbons in the fatty alcohol residue, such as lauryl (or coconutfatty alcohol) sulfate. Other suitable members of this class are thesulfuric acid esters of polyhydric alcohols incompletely esterified withhigher fatty acids; the oleic acid ester of isethionic acid; the higherfatty acids (e.g. coconut) ethanolamide sulfates; the higher fatty acidamides of amino alkyl sulfonic acids, e.g. laun'c acid amide of taurine;and the like.

These sulfates and sulfonates are used in the form of theirwater-soluble salts, such as the alkali metal and nitrogen-containing,e.g. lower alkylolamine, salts. Examples are the sodium, potassium,ammonium, isopropanolamine, mono-and triethanolamine salts of saidhigher alkyl benzene sulfonate, higher alkyl sulfate and the like.

Typical specific examples are:

the sodium salt of a sulfate ester of an alkylphenoxypoly (ethyleneoxy)ethanol, the ammonium salt of this sulfate ester, sodium methyl oleyltaurate, sodium alkyl naphthalene sulfonate, alkyl aryl sodiumsulfonate, sodium tetraphydronaphthalene sulfonate, sodium alkyl arylsulfonate, alkyl amido sulfate, cocomonoglyceride sulfate,dodecylbenzene sodium sulfonate, dodecylbenzene sulfonic acid,tridecylbenzene sodium sulfonate, fatty alcohol sodium sulfate, sodiumdodecyl diphenyl oxide disulfonate, sulfonated castor oil,polyethoxyalkyl phenol sulfonate triethanolamine salts, sodiumtriethanolamine alkyl aryl sulfonate, magnesium lauryl sulfate,potassium lauryl sulfate, sodium lauryl ether sulfate, ammonium laurylether sulfate, sodium tallow sulfate, dodecylbenzene sodium sulfonate,oleyl methyl tauride, ammonium lauryl sulfate, amide sulfonate, and thelike.

In general, suitable nonionic surfactants include those such as producedby the introduction of alkylene oxide group into an organic hydrophobiccompound or group having an aliphatic or aromatic structure. Thehydrophobic organic group generally contains at least eight carbon atomsand up to about 30 carbon atoms. Condensed with the hydrophobic groupare at least five and preferably up to about 50 alkylene oxide groups.It is preferred to use the polyoxyethylene condensates derived fromethylene oxide. It is preferred to use the polyalkylene oxidecondensates of alkyl phenol, such as the polyoxyethylene ethers of alkylphenols having an alkyl group of at least about six, and usually abouteight to 12 carbons, and preferably eight to nine carbon atoms, and anethylene oxide ratio (No. of moles per phenol) of about 7.5, 8.5, 11.5or 20, though the number of ethylene oxide groups will be usually fromabout eight to 40. The alkyl substituent on the aromatic nucleus may bedi-isobutylene, diamyl, polmerized propylene, dimerized C -C olefin, andthe like.

Further suitable nonionics are the polyoxyalkylene esters of organicacids, such as the higher fatty acids, rosin acids, tall oil acids, oracids from the oxidation of petroleum, et cetera. These polyglycolesters will contain usually from about 12 to about 30 moles of ethyleneoxide or its equivalent and about eight to 22 carbons in the aryl group.Suitable products are refined tall oil condensed with 16 or 20 ethyleneoxide groups, or similar polyglycol esters of lauric, stearic, oleicacids, etc.

Additional nonionic agents are the polyalkylene oxide condensates withhigher fatty acid amides, such as the higher fatty acid primary amides,monoand diethanolamides. Suitable agents are coconut fatty acid amidecondensed with about to 50 moles of ethylene oxide. The fatty acyl groupwill have similarly about eight to 22 carbons, and usually about 10 to18 carbon atoms, in such products. The corresponding sulfonamides may beused also if desired.

Other suitable polyether nonionics are the polyalkylene oxide ethers ofhigh aliphatic alcohols. Suitable fatty alcohols having a hydrophobiccharacter, preferably eight to 22 carbons, are lauryl, myristyl, cetyl,stearyl and oleyl alcohols which may be condensed with an appropriateamount of ethylene oxide, such as at least about 6, and preferably about10 to 30 moles. A typical product is oleyl alcohol condensed with aboutl2, or moles of ethylene oxide. The corresponding higher alkylmercaptans or thioalcohols condensed with ethylene oxide are suitable inthe present invention also. The water-soluble polyoxyethylenecondensates with hydrophobic polyoxypropylene glycols may be employedalso, e.g. the ethylene oxide condensates with condensates of propyleneoxide and propylene glycol.

Further suitable nonionic materials are the higher fatty acidalkanolamides, such as the monoethanolamides, diethanolamides andisopropanolamides wherein the aryl radical has about 10 to 14 carbonatoms and amine oxides. Examples are coconut (or equivalent lauric),capric and myristic diethanolamide, onoethanolamide andisopropanolamide, dodecyl dimethyl amine oxide and dimethylacetoxyalkylamine oxide where alkyl is C C Generally, these surfactantscomprise from 0.05 to 10 per cent by weight, and preferably from 0.5 to3 percent of the reaction mixture and the latex added to the liquidhousehold bleach. Desirably the bleach composition has a surface tensionof 45 dynes/centimeter or less by virtue of the pressure of thesurfactant.

The optical brighteners useful herein include that species of dyes whichare fluorescing compounds, generally optically colorless andnonabsorptive in the visible portion of the spectrum. Generally,suitable brighteners are aromatic or heterocyclic compounds having aseries of conjugated double bonds.

Primary among typical compounds useful herein are:

l. The derivatives of 4,4'-diaminostilbene-2,2 disulfonic acid,particularly the bistriazinyl, bisacyl and mixed acyl triazinylderivatives. Napthotriazolylstilbene sulfonic acid may be mentioned.Azinyl radicals may be substituted on the carbons of the heterocyclicring with many radicals including hydroxy, amino, alkoxy, hydrocyalkoxy,chloro, thio, alkoxybenzoyl, anilino, morpholino and others. Acylradicals include acetyl, phenoxyacetyl, alkoxybenzoyl toluyl, benzoyland aminobenzoyl. Benzoyl acyl radicals are generally substituted in theortho and/or para position, eg with p-acetamino, methyl, methoxy,acetoxy, 2-hydroxyethoxy, haloalkoxy or alkenyloxy groups. The sulfonicacid group substituent in the stilbene may be replaced with an electrondonor radical such as alkyl, alkoxy or sulfamyl;

11. The derivatives of dibenzothiophene-S, S-dioxide, specifically3,7diaminodibenzothiophene 2,8-disulfonic acid- 5, 5-dioxide in whichthe preferred acyl groups are alkoxybenzoyl groups. See, e.g. US. Pat.Nos. 2,563,795; 2,573,652; 2,702,759; 2,719,155; and 2,733,165 which areincorporated herein by reference; and

III. The azoles, prepared generally by diazotization of 4-aminostilbene-2-sulfonic acid, coupling with an orthocouplingnaphthylamine derivative (or benzene or a heterocylic) and oxidation tothe triazole. See US. Pat. Nos. 2,784,197; 2,713,057; 2,817,665;2,784,184; 2,972,611; 2,640,056; 2,639,990; Brit. Pat. No. 808,113;Belg. Pat. No. 572,498; US. Pat. Nos. 2,765,304; 2,765,239; and Ger.Pat. No. 735,478, which are incorporated herein by reference; e.g.naphthotriazole, bis-benzimidazolyl compounds and benzimidazole;

IV. Coumarin and derivatives;

V. Pyrazine and derivatives; and

VI. 4Aminonaphthalimide.

In addition, dyes and pigments may be used in place of or with theforegoing, e.g. chromates, polysulfides, thianaphthanones andphthalocyanine such as potassium dichromate, Ultramarine blue,Sulfanthrene Pink FFD Paste and Monastral Fast Green GWD, for thepurpose of contributing blue light of various tints. As used herein theterm optical brightener compound" is intended to be inclusive of thesecolorants as well as the fluorescing, colorless dyes.

The invention is illustrated by the following examples, in which allparts and percentages are by weight.

EXAMPLE 1 A. Polymer Preparation Dissolve five parts of dioctyl ester ofsodium sulfosuccinic acid and 2 parts of tetrasodium N-(l,2-dicarboxyethyl)-N-octadecyl-sulfosuccinamate in 700 parts of water.To this add 50 parts of methacrylic acid followed by 30 parts of a 25percent aqueous solution of sodium vinyl sulfonate. Dissolve five partsof Calcofluor ALF (optical brightener compound) in 250 parts of styrene.Emulsify the styrene solution in the aqueous phase and carry out thepolymerization by heating the emulsion to F. and adding one part ofsodium persulfate catalyst. The temperature rises to about -200 F. fromthe exothermic heat of reaction. Cool to 130 F. and add 30 parts of a 25percent aqueous solution of sodium vinyl sulfonate followed by 250 partsof styrene. Stir for 30 minutes holding at 130 F. and then add catalystand polymerize the second monomer addition with the heat of the exothermand cool.

B. Bleach Composition Preparation Add 0.5 percent of the latex obtainedin Part A to a 5 percent aqueous solution of sodium hypochlorite.

C. Stability Fluorescence is evaluated at periodic intervals. The bleachshows fluorescence initially and for 3 months of 70 F., the normal shelflife for hypoehlorite bleach. Fabric washed with the bleach showsgreater whitening (brightening) both on visual and instrumentalinspection.

EXAMPLE 2 Duplicate Example 1 but employ 300 parts of vinyl toluene inthe first polymerization reaction mixture and 200 parts thereof in thesecond polymerization reaction mixture, in place of the styrene inExample 1. In Part C, evaluation of fluorescence shows continuingfluorescence after 3 months at 70 F.

EXAMPLE 3 Duplicate Example 1 but employ 30 parts of acrylic acid in thefirst polymerization reaction mixture and 20 parts in the secondpolymerization reaction mixture. The brightener containing latex isstable in 6 percent sodium hypochlorite bleach by fluorescence testing 9CONTROL 1 Duplicate Example 1 but mix the methacrylic acid first withstyrene and then add to the aqueous surfactant solution, followed byheating to polymerize. In parts B and C the emulsion which had similarsize particles and the same milky appearance prior to addition to thebleach as the Example emulsion, shows immediate physical deteriorationand quickly demulsifies and settles as a flocculated mass in the holdingvessel.

We claim:

1. Optically brightened liquid bleach composition consisting essentiallyof an aqueous solution of a hypochlorite ion generating bleaching agentand an optical brightener compound in an effective amount, saidbrightener compound being protectively carried in said solution by afinely particulate styrene polymer carrier which is dispersed throughsaid solution and comprises particles having an inner portion consistingessentially of said optical brightener compound and a styrene-acrylicpolymer formed by polymerization of styrene in which said compound hasbeen predissolved, with an acrylic monomer and an outer portion formingan encapsulating layer over the inner portion and consisting essentiallyof styrene polymer free of said compound, said particle comprising per100 parts of polymer from 65 to 98 parts of a styrene monomer selectedfrom the group consisting of styrene and alkyl substituted styrene inwhich the alkyl group contains from one to four carbon atoms andconversely from two to 35 parts of methacrylic or acrylic acid monomercopolymerized therewith, said inner portion polymer containing a majorproportion but less than 90 percent by weight of said styrene and atleast a major weight proportion of said acid monomer, said outer portionpolymer containing the balance of said monomers.

2. Composition according to claim 1 in which said particles contain from0.5 to 5 percent by weight of said compound based on the weight of thestyrene in said polymer.

3. The composition according to claim 1 in which said carrier issubstantive to fabric.

4. The composition according to claim 1 in which said hypochlorite iongenerating compound is a heterocyclic N- chlorimide.

5. The composition according to claim 1 in which said hypochlorite iongenerating compound is sodium hypochlorite.

6. The composition according to claim 1 in which said styrene monomer isvinyl benzene.

7. The composition according to claim 1 in which said carrier is presentin said solution in an amount between 0.05 and 5 percent by weight.

8. Composition according to claim 1 in which said particles have anaverage particle size between 0.5 and 2 microns.

9. Composition according to claim 1 in which said particles comprise per100 parts from 88 to 92 parts of styrene monomer and from eight to 12parts of methacrylic or acrylic acid.

10. Composition according to claim 1 in which said inner portioncontains from 60 to weight percent of said styrene and from 50 to weightpercent of said acid.

11. The composition according to claim 5 in which said solution has a pHof at least 10.

12. The composition according to claim 11 in which the hypochlorite ionis present in an amount between 1 and 10 percent by weight.

2. Composition according to claim 1 in which said particles contain from0.5 to 5 percent by weight of said compound based on the weight of thestyrene in said polymer.
 3. The composition according to claim 1 inwhich said carrier is substantive to fabric.
 4. The compositionaccording to claim 1 in which said hypochlorite ion generating compoundis a heterocyclic N-chlorimide.
 5. The composition according to claim 1in which said hypochlorite ion generating compound is sodiumhypochlorite.
 6. The composition according to claim 1 in which saidstyrene monomer is vinyl benzene.
 7. The composition according to claim1 in which said carrier is present in said solution in an amount between0.05 and 5 percent by weight.
 8. Composition according to claim 1 inwhich said particles have an average particle size between 0.5 and 2microns.
 9. Composition according to claim 1 in which said particlescomprise per 100 parts from 88 to 92 parts of styrene monomer and fromeight to 12 parts of methacrylic or acrylic acid.
 10. Compositionaccording to claim 1 in which said inner portion contains from 60 to 80weight percent of said styrene and from 50 to 100 weight percent of saidacid.
 11. The composition according to claim 5 in which said solutionhas a pH of at least
 10. 12. The composition according to claim 11 inwhich the hypochlorite ion is present in an amount between 1 and 10percent by weight.